The present invention relates to an electrical connector, and particularly to an electrical connector for reliably connecting with a mating connector and for providing excellent shielding and grounding effects.
Nowadays, a greater demand is being placed on electronic devices to be multi-functional. Thus, a high density of electrical elements are required to be assembled within the device, which increases electromagnetic interference between components thereby adversely affecting signal transmission. An electrical connector is used for transmitting signals between electronic devices. A shielding system is commonly assembled with the connector to minimize the effects of electromagnetic interference and ensuring proper signal transmission.
A conventional shielding system is disclosed in U.S. Pat. No. 4,337,989. Referring to FIG. 1, an electrical connector 1' comprises a U-shaped shield cover 3' enclosing the electrical connector 1'. The shield cover 3' is a component of a shielding system for shielding the connector 1' from outer electromagnetic interference. The shield cover 3' forms a pair of mounting plates 5' and an aperture 7' is formed in each mounting plate 5'. The shield cover 3' encloses a dielectric body 10' and is then mounted to a mating circuit board 9'. A metal sheet 90' covers the circuit board 9'. The sheet 90' defines a pair of screw holes 91' corresponding to the apertures 7' of the shield cover 3', and a plurality of receiving holes 92' for receiving corresponding tail portions 11' of terminals 12' fixed in the body 10'. Thus, the housing 3' can be screwed to the circuit board 9' through the mounting apertures 7' and the corresponding screw holes 91' thereby achieving good shielding effects. However, the screw mounting mode results in low manufacturing efficiency. Moreover, the mounting plates 7' occupy additional space on the circuit board 9' thereby limiting circuitry layers of the circuit board 9'.
An integrate type of shielding system, disclosed in U.S. Pat. No. 5,073,130 and Taiwan Patent Application No. 81110335, includes a housing enclosing a dielectric body of an electrical connector receiving a plurality of contacts therein and commonly forming a pair of grounding legs. The grounding legs are inserted into a mating circuit board thereby forming a grounding circuit to discharge static electricity via the circuit board. Such a shielding system can achieve good shielding and grounding effects. However, the grounding legs are unable to quickly discharge the large quantity of static electricity produced by newly developed high frequency electrical elements. Therefore, a large quantity of static electricity may accumulate in electrical connectors and may produce sparks via any tines formed on the electrical connector, thereby damaging the electrical connectors and the mating circuit board. Moreover, the retention force provided by the grounding legs is insufficient for properly fixing the electrical connector to the mating circuit board. Thus, reliable and stable signal transmission between the connector and the mating circuit board can not be ensured. Furthermore, contacts of conventional connectors may become deformed at free ends thereby adversely affecting the stability of signal transmission.